Mitchell Valdés-Sosa

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The association of enumeration and number comparison capacities with arithmetical competence was examined in a large sample of children from 2nd to 9th grades. It was found that efficiency on numerical capacities predicted separately more than 25% of the variance in the individual differences on a timed arithmetical test, and this occurred for both younger(More)
Patients with prosopagnosia are unable to recognize faces consciously, but when tested indirectly they can reveal residual identification abilities. The neural circuitry underlying this covert recognition is still unknown. One candidate for this function is the partial survival of a pathway linking the fusiform face area (FFA) and anterior-inferior temporal(More)
Rightward shifts in attention are a common consequence of brain injury. A growing body of evidence appears to suggest that increases in attentional load, and decreases in alertness can lead to rightward shifts in attention in healthy and patient populations. It is unclear however whether these factors affect spatial biases in attention at the level of(More)
Familiar faces convey different types of information, unlocking memories related to social-emotional significance. Here, the availability over time of different types of memory was evaluated using the time-course of P3 event related potentials. Two oddball paradigms were employed, both using unfamiliar faces as standards. The infrequent targets were,(More)
Attending to objects implies the concurrent process of features that are analyzed in different visual subsystems or domains. Previous works have shown that attention cannot be simultaneously directed to the components of motion present in two transparent surfaces [M. Valdés et al., Cognition 66 (1998) B13-B23], even though they occupy overlapping regions of(More)
In this study, we explored the influence of an irrelevant translational event on the automatic capture of attention to one of two superimposed surfaces defined by transparent motion. The results showed that an irrelevant translation on one surface did not automatically capture the subjects' attention if the attentional resources have been endogenously(More)
During transparent motion, attention to changes in the direction of one illusory surface will impede recognition of a similar event affecting the other surface if both are close together in time. This is a form of object-based attentional blink (AB). Here, we show that this AB is related to a smaller N200 response to the change in direction and that the(More)
Amygdala structural and functional abnormalities have been associated to reactive aggression in previous studies. However, the possible linkage of these two types of anomalies has not been examined. We hypothesized that they would coincide in the same localizations, would be correlated in intensity and would be mediated by reactive aggression personality(More)
Although Capgras delusion (CD) patients are capable of recognizing familiar faces, they present a delusional belief that some relatives have been replaced by impostors. CD has been explained as a selective disruption of a pathway processing affective values of familiar faces. To test the integrity of connections within face processing circuitry, diffusion(More)
We analyze the functional significance of different event-related potentials (ERPs) as electrophysiological indices of face perception and face recognition, according to cognitive and neurofunctional models of face processing. Initially, the processing of faces seems to be supported by early extrastriate occipital cortices and revealed by modulations of the(More)